(1) Field of the Invention
This invention relates to the purification of human immune interferon. More particularly the invention relates to a process for the purification of crude human immune interferon from induced human peripheral blood leukocytes by a series of steps to remove contaminants and yield a near homogeneous interferon preparation.
Interferon is a glycoprotein whose synthesis in cells is principally induced by viruses or mitogens. Interferons are classified into three major species designated IFN-.alpha. (leukocyte), IFN-.beta. (fibroblast), IFN-.gamma. (Immune). Leukocyte and fibroblast interferons are induced by viruses or synthetic polynucleotides. Immune-type interferons are usually induced in primed lymphocytes by a specific antigen or in unprimed lymphocytes by T-cell mitogens. The thus produced interferons are associated with a variety of contaminants which include proteins and are referred to herein as "crude interferon."
(2) The Prior Art
Purification and characterization of interferons have been studied extensively and the subject has been reviewed recently in "The Interferon System," William E. Stewart II, Springer-Verlag, New York, N.Y. (1979). Among the various procedures for purifying human immune interferon is the procedure described by Langford, et al., in "Large-Scale Production and Physicochemical Characterization of Human Immune Interferon," Infection and Immunity, Vol. 26, pp. 36-41 (1979), who studies the use of Controlled Pore Glass (CPG) adsorption chromatography and gel-filtration chromatography for purifying HuIFN-.gamma.. Another purification procedure is taught by Wiranowska-Stewart, et al., in "Production, Partial Purification and Characterization of Human and Murine Interferons-Type II," Molecular Immunology, Vol 12, pp. 625-623, (1980), which describes the use of CPG-adsorption chromatography and poly (U) Sepharose affinity chromatography. A third procedure was published by de Ley, et. al., in "Interferon Induced in Human Leukocytes by Mitogens: Producton, Partial Purification and Characterization," European J. of Immunology, Vol. 10, pp. 877-833 (1980), describes the use of Controlled Pore Glass adsorption chromatography and eluting from the column with an ethylene glycol solution and gel-filtration chromatography. A fourth procedure by Yip, et al., entitled "Partial Purification and Characterization of Human (Immune) Interferon," was published in Proc. Nat'l Acad. Sci., U.S.A., Vol 78, pp. 1601--1605 (1981), where the use of Controlled Pore Glass adsorption chromatography, concanavalin-A Sepharose affinity chromatography and gel-filtration chromatography are described.